The present invention relates to a terminal device, a program, an information storage medium, and a data processing method capable of protecting data.
In the case of downloading game data to a portable telephone and performing a game, a problem may occur in which the game data is read by a user operation.
As a method for solving such a problem, a method of dividing the game data, a method of encrypting the game data, and the like may be employed.
Japanese Patent Application Laid-Open No. 2003-143131 discloses an electronic information management device which divides encrypted data into a plurality of pieces, writes each piece while designating random physical position information, creates a correspondence table including the physical position information, writes an encrypted correspondence table obtained by encrypting the correspondence table while designating the physical position information, and transmits the physical position information to a management server device, so that the stored contents are prevented from being deciphered when a storage device is analyzed.
Japanese Patent Application Laid-Open No. 2004-46431 discloses a portable telephone which records encrypted data in an external recording device using a secret key encryption method, decrypts and displays the encrypted data so that the contents recorded in a built-in recording section with a relatively small storage capacity can be backed up while preventing infringement of the copyright of the contents and privacy.
However, since these methods store the entire encrypted data in a single storage section in the same manner as in the related art, the storage section must have a large storage capacity.
The method disclosed in Japanese Patent Application Laid-Open No. 2004-46431 records the encrypted data in the external recording device. However, it is preferable to store the encrypted data in the storage section inside the device in order to prevent infringement of copyright and privacy.